Both choleolithiasis and hepatolithiasis are considered to be idiopathic, though it is though that any condition that causes of bile may contribute to calculi formation. Cholangiohepatitis or stenosis of the common bile duct due to fibrosis of the duodenum surrounding the opening of the bile duct may lead to bile stasis. The formation of calculi in the common bile duct or in the intrahepatic bile ducts causes partial or complete obstruction of the lumen of the bile duct. This impedes the excretion of bile into the duodenum causing bile to back up in the liver. Enlargement of the liver, or , and hepatic dysfunction occur as a result of the obstruction of the bile ducts. Middle aged horses from nine to fifteen years of age are reported to present most often with calculi formation in the bile ducts. The clinical presentations of choleolithiasis and hepatolithiasis are similar. The clinical signs and symptoms include weight loss, abdominal pain, icterus, intermittent fever, hepatomegaly, dilation of the bile ducts and . Diagnosis is made through ultrasound showing hepatomegaly and serology showing increased Bilirubin, GGT and bile acid levels.
Treatment is the surgical removal of the calculi from the bile ducts.
Prognosis for choleolithiasis or hepatolithiasis is poor to grave. Surgical removal of the calculi is often unsuccessful, and calculi may reoccur.
Chronic Hepatitis
Chronic hepatitis is described as the progressive inflammation of the liver.
It may be idiopathic, or it can be caused by infection of the liver, liver toxicity or immune mediated reactions against liver tissue. blood vessels, then spreads throughout the liver. Inflamed areas become necrotic and then fibrotic as scarring replaces the damaged liver tissue. Loss of functional liver tissue impairs all aspects of liver function. Generally, inflammation starts in the tissue surrounding the bile ducts or the
Horses affected by
disease or infection are predisposed to developing chronic hepatitis.
The clinical presentation of chronic hepatitis includes anorexia, weight loss, lethargy, icterus, hepatic encephalopathy, diarrhea, photosensitivity, fever, haemorrhage and and sloughing of the coronary band.
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